x1, y1, x2, y2 = map(float, raw_input().split())
print ((x1-x2)**2 + (y1-y2)**2)**0.5 x1, y1, x2, y2 = map(float, raw_input().split()) x1 map(float, raw_input().split()) map float raw_input().split() ().split () raw_input split y1 x2 y2 print ((x1-x2)**2 + (y1-y2)**2)**0.5 print ((x1-x2)**2 + (y1-y2)**2) print (x1-x2)**2 + (y1-y2)**2 (x1-x2)**2 x1-x2 x1 x2 2 (y1-y2)**2 y1-y2 y1 y2 2 0.5 x1, y1, x2, y2 = map(float, raw_input().split()) map(float, raw_input().split()) x1 y2 = map(float, raw_input().split()) map(float, raw_input().split()) y2 x2, y2 = map(float, raw_input().split()) map(float, raw_input().split()) x2 y1, x2, y2 = map(float, raw_input().split()) map(float, raw_input().split()) y1
x1, y1, x2, y2 = map(float, raw_input().split())
print ((x1-x2)**2 + (y1-y2)**2)**0.5